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Primordial Lithium: New Reaction Rates, New Abundances, New Constraints

机译：原始锂：新的反应速率，新的丰度，新的约束

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Newly measured nuclear reaction rates for sup 3 H( alpha , gamma ) sup 7 Li (higher than previous values) and sup 7 Li(p, alpha ) sup 4 He (lower than previous values) are shown to increase the sup 7 Li yield from big bang nucleosynthesis for lower baryon to photon ratio (eta less than or equal to 4 x 10 sup -10 ); the yield for higher eta is not affected. New, independent determinations of Li abundances in extreme Pop II stars are in excellent agreement with the earlier work of the Spites and give continued confidence in the use of sup 7 Li in big bang baryon density determinations. The new sup 7 Li constraints imply a lower limit on eta of 2 x 10 sup -10 and an upper limit of 5 x 10 sup -10 . This lower limit to eta is concordant with that obtained from considerations of D + sup 3 He. The upper limit is consistent with, but even more restrictive than, the D bound. With the new rates, any observed primordial Li/H ratio below 10 sup -10 would be inexplicable by the standard big bang nucleosynthesis. A review is made of the strengths and possible weaknesses of utilizing conclusions drawn from big bang lithium considerations. An appendix discusses the null effect of a factor of 32 increase in the experimental rate for the D(d, gamma ) sup 4 He reaction. 28 refs., 1 fig. (ERA citation 12:019268)

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